Morphology Of Oxide Research Articles

Effects of Temperature Fluctuations on Surface Mobility of Atomic Steps and Oxidation Dynamics in High-Temperature Alloys.

In contrast to the traditional perspective that thermal fluctuations are insignificant in surface dynamics, here we report their influence on surface reaction dynamics. Using real-time low-energy electron microscopy imaging of NiAl(100) under both vacuum and O2 atmospheres, we demonstrate that transient temperature variations substantially alter the direction of atom diffusion between the surface and bulk, leading to markedly different oxidation outcomes. During heating, substantial outward diffusion of atoms from the bulk to the surface results in step growth. Conversely, cooling induces considerable inward diffusion of adatoms, producing a distinct oxide morphology. In both scenarios, initially formed oxide islands impede local atomic step mobility, thereby increasing step length due to mass transfer between the surface and bulk, with atomic steps acting as adatom sinks during heating and sources during cooling. Furthermore, we show that this pinning effect on atomic step mobility can be mitigated by applying persistent temperature fluctuations. Understanding these nuances is vital for accurately predicting and dynamically manipulating the performance of active materials in various chemical processes under transient thermal conditions.

Effects of SiC oxide morphology on bearing capacity of SiC and mechanical properties of SiCp/Al-Si-Mg composites

Effects of SiC oxide morphology on bearing capacity of SiC and mechanical properties of SiCp/Al-Si-Mg composites

Phase tailoring of silver oxide thin films for improved antimicrobial activity

This paper reports on routes to control the silver oxide phase and morphology in thin films to enhance their antimicrobial efficacy. The Ag:O atomic ratio was tailored during the pulsed laser deposition process by adjusting the O2 environment, and thus, a wide range of silver oxide phases ranging from Ag to AgxO was achieved. Simultaneously, the morphology was controlled from island-like (Volmer–Weber) formations to nanoparticle arrays, ultimately culminating in cauliflower-like dendrite structures. Through this synergistic approach, enhancing the oxygen content while expanding the active surface area yielded optimal enhancement of the antimicrobial properties. Remarkably, films deposited at elevated O2 pressures exhibited heightened inhibitory effects against bacterial biofilms, with films featuring nanoparticle morphology demonstrating notable antistaphylococcal efficacy.

A green approach for morphology and size-controlled fabrication of cerium oxide using leaf extract of Mangifera indica for photocatalytic activities

AbstractGreen synthesis offers environmental benefits and prevents harmful by-products. This article reports on the green synthesis of cerium oxide nanoparticles (CeO2 NPs) using aqueous leaf extract of Mangifera indica (M. indica) and an investigation of its photocatalytic activity. M. indica has not yet been reported to be used in the synthesis of CeO2 NPs. CeO2 NPs were synthesized using two different precursors; Ce(NO3)3·6H2O and CeCl3·7H2O with two different concentrations of aqueous leaf extracts of M. indica at 80 °C. The products were analyzed using X-ray diffraction (XRD), Fourier Transform-Infrared spectroscopy (FT-IR), and field emission scanning electron microscopy (FE-SEM). The two different precursors have shown differences in the structural and morphological properties of the synthesized CeO2 NPs. The XRD results indicated that the crystallite size was in the range from 13 to 18 nm. FT-IR detected the presence of organic functional groups on the surface of the synthesized CeO2 NPs. The morphology and average particle size of the produced CeO2 NPs, which ranged from 42 to 90 nm, were revealed by FE-SEM. Photocatalytic activities findings showed that CeO2 synthesized with a low concentration of aqueous leaf extract and Ce nitrate as precursor showed the highest percentage (17–19%) of photocatalytic transformation of 4-nitrophenol to 4-nitrophenolate ion under visible light irradiation. This confirms that the amount of extract and type of anions play a critical role in the fabrication of responsive and active CeO2 NPs. This also confirms that CeO2 synthesized through a green synthesis method may potentially give a response for visible light irradiation activities.

Regulating Oxides Enhances the Mechanical Properties of Additively Manufactured Martensitic Stainless Steel

Laser powder bed fusion (LPBF), a subset of additive manufacturing, is used increasingly to produce martensitic stainless steels (MSSs) for aerospace and medical devices. However, excessive oxygen content in MSS powder generally impairs the mechanical properties of parts produced via LPBF. To investigate the effect of oxides on additively manufactured MSS, this study utilizes powders with various oxygen contents and printed numerous samples under different parameters. This article systematically analyzes the source, morphology, and distribution of oxides in MSS samples and their effects on the microstructure and mechanical properties. It is found that MSS samples printed with high‐oxygen powder exhibit higher strength and hardness. The average hardness of high‐oxygen powder‐printed samples increases by 14.2 HV3 over low‐oxygen samples. Additionally, their average tensile and yield strengths of 1025.97 and 809.18 MPa show increases of 3.36% and 17.33%, respectively. This provides a reference for regulating oxides in additively manufactured MSS and potentially benefiting from them.

Asphalt-Aggregates Interface Interaction: Correlating Oxide Composition and Morphology with Adhesion

The adhesion between asphalt and aggregates is a complex physicochemical interfacial interaction that plays a critical role in determining the durability of asphalt pavement. This paper aims to investigate the determination mechanism of oxide composition and morphology of aggregates to their interfacial interaction and adhesion with asphalt, thereby optimizing the adhesion evaluation indicators of aggregates. Herein, the adhesion and interaction properties of aggregates were evaluated by photoelectric colorimetric, water boiling methods, and dynamic shear rheometer. The morphology and chemical compositions of 11 aggregates were characterized using X-ray diffraction, X-ray fluorescence, and scanning electron microscopy, thereby classified into 3 categories based on their oxide composition. The results indicate that the chemical composition of the aggregates is a crucial factor influencing adhesion rates, while micro-roughness impacts adhesion rates to varying degrees across different aggregate groups. Oxide composition was found to be a reliable predictor of adhesion properties, and incorporating surface roughness indicators improved the accuracy of adhesion rate prediction models. Both rheological indicators proved effective in characterizing the adhesion properties of aggregates, though they exhibited varying sensitivities depending on the aggregates categories.

Antibacterial Properties and Biocompatibility of Multicomponent Titanium Oxides: A Review.

The simple oxides like titania, zirconia, and ZnO are famous with their antibacterial (or even antimicrobial) properties as well as their biocompatibility. They are broadly used for air and water filtering, in food packaging, in medicine (for implants, prostheses, and scaffolds), etc. However, these application fields can be broadened by switching to the composite multicomponent compounds (for example, titanates) containing in their unit cell, together with oxygen, several different metallic ions. This review begins with a description of the synthesis methods, starting from wet chemical conversion through the manufacturing of oxide (nano)powders toward mechanosynthesis methods. The morphology of these multicomponent oxides can also be very different (like thin films, complicated multilayers, or porous scaffolds). Further, we discuss in vitro tests. The antimicrobial properties are investigated with Gram-positive or Gram-negative bacteria (like Escherichia coli or Staphylococcus aureus) or fungi. The cytotoxicity can be studied, for example, using mouse mesenchymal stem cells, MSCs (C3H10T1/2), or human osteoblast-like cells (MG63). Other human osteoblast-like cells (SaOS-2) can be used to characterize the cell adhesion, proliferation, and differentiation in vitro. The in vitro tests with individual microbial or cell cultures are rather far away from the real conditions in the human or animal body. Therefore, they have to be followed by in vivo tests, which permit the estimation of the real applicability of novel materials. Further, we discuss the physical, chemical, and biological mechanisms determining the antimicrobial properties and biocompatibility. The possible directions of future developments and novel application areas are described in the concluding section of the review.

Electrochemical Properties of Copper Oxides Obtained from Layered Copper Hydroxide Acetate for Nonenzymatic Glucose Sensing

Nowadays, glucose sensing is a crucial role for capturing the status of diabetes, and its precise sensing directly contributes to prevent such diseases from exacerbating. While the use of enzymes such as glucose oxidase is known to be a major stream in glucose sensing. the issues of cost. Reusability. and chemical stability are still room for development. One of the non-enzyme system, copper oxides, would be a game-changer in place of enzymes.1 In addition to some great features which can address the aforementioned issues, copper oxides have a unique characteristic of their microstructure.1 Because the microstructure (surface area) greatly dictates the sensing ability, several literatures report the correlation between sensing ability and the microstructure of copper oxides. 2,3 With this keep in mind, we prepared several copper oxides with different morphology by using a one-pot fabrication process based on electrochemistry and investigate the effect of various morphologies of copper oxides on the glucose performance (Fig. 1A). We prepared copper oxides by reducing a layered copper hydroxide acetate (Cu2(OH)3Ac-) with various voltages.4 First, Cu(CH3COO)2・H2O was added into ultra-purified water and was allowed in a thermostatic bath at 60 ℃ for 30 h to obtain Cu2(OH)3Ac-.4 The resultant Cu2(OH)3Ac- was mixed with water and was drop casted onto a carbon paper. The obtained carbon paper incorporated with Cu2(OH)3Ac- was immersed in 0.1 M KHCO3 electrolyte and was exposed at the constant voltage of -1.2 V vs. Ag/AgCl for one hour to obtain copper oxide. (Figure. 1(A)) Figure 1(B) shows the cyclic voltammograms of carbon paper electrodes in the absence or presence of copper oxides in the electrolyte of 0.1 M NaOH with 5 mM glucose. For the carbon paper electrode, there is no oxidation current appeared in the voltage range of 0-0.8 V vs. Ag/AgCl, suggesting that the carbon paper itself is inert for electrochemical reactions in such voltage range. On the flipside, a significant oxidation peak appeared when the carbon paper incorporated with copper oxides was used. More importantly, the peak current has a strong relationship with glucose concentration (Figure 1(C)), suggesting the glucose concentration is electrochemically detectable. We will demonstrate and discuss the influence of the applied potential during the fabrication of copper oxides on the glucose response in the poster session.AcknowledgementsThe work was supported partly by Nippon Sheet Glass Foundation for Materials Science Engineering.References1) Y. Zhanga, N. Li, Y. Xiang, D. Wang, P. Zhanga, Y. Wang, S. Lu, R. Xu, J. Zhao, Carbon, 156, 506-513, (2020).2)P. D. Luna, R. Quintero-Bermudez, C. Dinh, M. B. Ross, O. S. Bushuyev, P. Todorović, T. Regier, S. O. Kelley, P. Yang, E. H. Sargent, Nat. Catal., 1(2), 103–110, (2018).3) A. R. Amirsoleimani, H. Siampour, S. Abbasian, G. B. Rad, A. Moshaii, Z. Zaradshan, Sens. Bio-Sens. Res., 42, 100589, (2023).4) S. Švarcová, M. Klementová, P. Bezdička, W. Łasocha, M. Dušek, D. Hradil, Cryst. Res. Technol., 46(10), 1051-1057, (2011). Figure 1

CO2 utilization for the synthesis of propylene carbonate from propylene oxide using CeO2–La2O3 mixed oxide under solventless condition

One of the most promising strategies for removing excess carbon dioxide from the atmosphere is CO2 utilization. Here, we describe the effective synthesis of propylene carbonate utilizing CeO2–La2O3 (Ce–La) mixed oxide, combining propylene oxide with carbon dioxide. The addition of La2O3 (La) to CeO2(Ce) resulted in an increase in oxygen vacancy, reducibility, and support–support interaction. Modifying the La:Ce ratio leads to a fine–tuning of the reducibility of the oxide, which can be explained by the formation of oxygen vacancies in the ceria lattice upon La addition. This modification also permits tailoring of the oxide morphology (lattice parameter, pore structure, particle size, and surface area). Powder X–ray diffraction (P–XRD), temperature programmed reduction by hydrogen (H2–TPR), Raman spectroscopy, BET surface area, and X–ray photoelectron spectroscopy (XPS) were used to analyze the physico–chemical properties of the developed materials. Additionally, it demonstrates excellent catalytic activity for the solvent–free cycloaddition of CO2 with propylene oxide, yielding 86%, and it maintains its high stability over five cycles without changing its shape.

Dual‐Site Anchors Enabling Vertical Molecular Orientation for Efficient All‐Perovskite Tandem Solar Cells

AbstractAll‐perovskite tandem solar cells (TSCs) are gaining increasing attention due to their potential to surpass the efficiency limit of single‐junction solar cells. However, as the bottom low‐bandgap subcells, tin‐lead (Sn‐Pb) perovskites suffer from severe nonradiative recombination at the interfaces due to their susceptibility to oxidation and poor crystalline morphology. Here a surface modifier 4‐(trifluoromethyl)benzhydrazide (TFH) is reported to construct a reductive chemical environment on the surface of perovskite films and protect them from water and oxygen erosion. TFH anchors onto the Sn‐Pb perovskites in a preferred vertical orientation through dual‐site binding, forming interface dipoles that facilitate charge extraction. The reductive hydrazine groups of TFH can effectively inhibit the oxidation of Sn2+ and I−, thereby reducing the defect density and energy disorder of Sn─Pb perovskites. Consequently, the TFH‐treated devices achieved a champion PCE of 22.88%, maintaining over 93% of the initial efficiency after continuous one‐sun illumination for 500 h. Combined with a 1.79 eV wide‐bandgap subcell, it has demonstrated a PCE of 28.17% in all‐perovskite TSCs.

Analysis of Oxide Layer Formation During Oxidation of AISI 4140 Steel at 1000 °C over Exposure Time

The high-temperature shaping of steels is accompanied by the formation of surface scales composed of oxide layers. However, the oxidation kinetics and morphology of these scales remain poorly understood. This study analyses the formation of oxide layers on AISI 4140 steel at varying oxidation times (20, 40 and 60 min) at 1000 °C. The analysis revealed the presence of hematite, magnetite, and transformed wustite in the oxide layers, along with clusters of alloying element oxides, predominantly chromium and iron oxide (FeCr2O4). There was a direct correlation between the duration of the oxidation process and the thickness of the scale and the number of defects observed in the material. The coating layer of alloying element oxides demonstrated insufficient adhesion to the steel substrate. Similarly, the oxides of alloying elements within this layer exhibited low cohesion among themselves. The alloying elements are present in all oxide layers, but in greater quantity in the layer in contact with the steel substrate, where a reduction in their concentrations was observed over time. This indicates that the alloying elements tend to disperse as the thickness of the alloying element oxide layer increases over time.

Effects of nickel-deactivations on zeolites-Y of different SiO2/Al2O3 ratios in catalytic cracking of hydrocarbons

Effects of nickel deactivation on catalytic activities of three types of zeolites-Y (Y-5.1, USY-5.2, and VUSY-12) with varying SiO2/Al2O3 ratios were studied in cracking of hydrocarbons. Physicochemical characteristics such as crystalline phases, Ni oxidation states, morphology, acidity, surface area, and thermal stability of the samples were analysed. XRD revealed the absence of observable nickel compounds below 5 wt%, with NiO phase emerging at higher concentrations. Surface areas decreased from 826 to 615 m2/g (Y-5.1), 786–686 m2/g (USY-5.2), and 762–571 m2/g (VUSY-12) at 30 wt% Ni. The total acid sites also reduced from 17.247 to 9.826 µmol/g (Y-5.1), 15.464–8.854 µmol/g (USY-5.2), and 7.094–4.876 µmol/g (VUSY-12). XPS confirmed Ni2+ states. Catalytic cracking tests using n-Heptane demonstrated increases in C5-C6 alkanes, olefins, hydrogen, and methane yields as nickel concentration increased, with respective values of 64 %, 28 %, 79 % and 68 % for Y-5.1; 62 %, 28 %, 76 %, and 62 % for USY-5.2; and 58 %, 21 %, 75 %, and 60 % for VUSY-12. A corresponding decrease in heavier components were observed. The study demonstrates that nickel modification significantly impacts the physicochemical properties and catalytic performance of zeolite-Y and these depend strongly on the SiO2/Al2O3 ratios. The study gives further insights into the structural and catalytic modifications induced by nickel doping in zeolites, highlighting the potential of nickel-modified zeolites in promoting undesirable hydrogen and gas.

Enhancing energy storage with binder-free nickel oxide cathodes in flexible hybrid asymmetric solid-state supercapacitors

The need for flexible electrode materials for the development of flexible supercapacitors has drawn scientific interest recently. We present the successful synthesis of nickel oxide thin films using the successive ionic layer adsorption and reaction (SILAR) method, with the use of three different cationic precursors. This paper provides comprehensive details on the synthesized nickel oxide structure, morphology, and elemental analysis in addition to its electrochemical characteristics, which include specific capacitance (SCs), charge transfer resistance, etc. The produced nickel oxide electrodes achieved specific capacity as 120 C g−1, 517 C g−1, and 1147 C g−1 with different nickel precursors such as nickel chloride, nickel nitrate, and nickel sulfate respectively, at a 1 mA cm−2 current density. A flexible hybrid asymmetric solid-state supercapacitor (FHASS) (S:NiO//PVA-KOH//CuS) device delivered SCs of 165 Fg−1 at a 0.5 mA cm−2 current density, with a maximum SE of 58.87 Wh kg−1 at SP 347 W kg−1. FHASS device exhibits capacitive retention and coulombic efficiency of between 79 % and 96 % after 5000 successful GCD cycles. Also, the device retained an outstanding 97 % of its capacitance at a 175º bending angle. Furthermore, to illustrate its real-world applicability, the constructed device underwent 30 s of charging to a lightning LED table lamp for 90 s. The fabricated device is bringing a new era of broad integration of device-grade applications.

Ce-Doped Iron Oxide Anticorrosive Coatings: Effect of c(Ce4+):c(Fe3+) Ratio on Structure, Morphology, and Coating Anticorrosion Performance

Utilizing hydrothermal methods, Ce-doped iron oxide nanoparticles were synthesized from precursor solutions under different c(Ce4:c(Fe3+) precursor solutions. The effects of the c(Ce4+):c(Fe3+) ratio in the precursor solutions on the nanoparticle morphology and nanoparticle structure of the Ce-doped iron oxide were investigated using X-Ray diffraction, transmission electron microscopy, and scanning electron microscopy. Fourier transform infrared spectroscopy (FTIR) was used to examine the bond energy strength of the Ce-doped iron oxide nanoparticles. The electrochemical properties of the Ce-doped iron oxide nanoparticles were tested using an electrochemical workstation and a saltwater immersion resistance test. The corrosion resistance of Ce-doped iron oxide coatings at different c(Ce4+):c(Fe3+) ratios was systematically analyzed, uncovering corrosion resistance mechanisms and self-healing capabilities. The results show that as the c(Ce4+):c(Fe3+) ratio decreases, the lattice constants of the samples increase along with the average grain size. Both smaller and larger c(Ce4+):c(Fe3+) ratios are detrimental to lattice distortion in α-Fe2O3. The reduced number of valence electrons provided by cerium ions in Ce-doped iron oxide hinders the generation of holes and exerts a minor influence on the crystal band structure, leading to weaker electrochemical stability. The Ce-doped iron oxide coating prepared at a c(Ce4+):c(Fe3+) ratio of 1:60 readily generates a higher number of reactive hydroxyl radicals during corrosion, thus exhibiting enhanced self-healing capabilities and corrosion resistance.

The effect of ultrasonic waves on the structure, morphology, and thermal conductivity of graphene oxide as nanofluids for direct absorption solar collector application

This research aims to explore how ultrasonic waves affect the structure and morphology of graphene oxide (GO) as a nanofluid, influencing its thermal conductivity (TC), stability, and photo-thermal conversion properties. GO was rapidly synthesized under ultrasonic bath irradiation using modified and improved Hummers' methods. Ultrasonic irradiation creates different structural and morphological defects in the GO that depend on the sonication time. The relationship between the exposure time to ultrasound and the creation of structural and morphological defects in graphene oxide nanosheets was investigated using UV–Vis, FTIR, Raman spectroscopies, AFM, and TEM analysis. The study examined how the structure and morphology of graphene oxide nanosheets affect the thermophysical and photo-thermal conversion properties of nanofluids by comparing heat transfer and stability. The simultaneous characterizing of the structure and morphology indicates that TC and stability are related to the sonication time. Indirect sonication with low intensity can carefully control the oxidation reaction of GO. Sonication for 30 min creates GO nanosheets that yield stable nanofluids with a 32.31 % enhancement in TC, with no extra treatment needed. This particular nanofluid has excellent photo-thermal conversion properties thanks to its high optical absorption, good stability, and thermal conductivity. This can increase the solar-thermal conversion efficiency (η) up to 72.5 %, making it a promising candidate for use as the working fluid in direct absorption solar collectors (DASCs)

Co-effect of perchlorate anions and hydrated protons on the electrochemical formation of Adams’ catalyst

The structure and morphology of oxide on the metal electrodes are strongly linked with the activity and stability of the electrocatalysts. Herein, the novel co-effect of anion and hydrated proton on structure of PtO2 formation is observed during the oxidation of water on Pt(100) preferentially oriented nanoparticles with in situ Raman spectroscopy and XPS. Higher concentrations (≥1.5 M) of non-specifically adsorbed perchlorate in 0.1 M perchloric acid solution facilitated the formation of crystalline α−PtO2 during the electro−oxidation of Pt(100), and no crystalline α−PtO2 was obtained without acid. Higher acidity electrolyte solution favors the formation of crystalline α–PtO2, indicating that proton plays a key role since specifically adsorbed sulfate without sulfuric acid did not lead to the formation of crystalline α–PtO2. A model containing anions, protons, and water molecules co-adsorbed on the Pt surface is constructed during density functional theory (DFT) calculations, which well explains the formation of crystalline α–PtO2 depending on anion and proton. The study findings provide an alternate approach for environmentally friendly and controllable preparation of Adams’ catalyst and an atomic–level understanding of oxide formation on Pt electrodes, which is essential for developing the next–generation electro-catalyst with exceptional performance and stability.

Tuning the morphology and surface structure of MnOx@GF through Ce for high-efficiency degradation of Rhodamine B by electro-Fenton

Widespread and ineffective dye treatment in aquatic environment leads to serious pollution problems, threatening ecology and human health. Herein, manganese cerium bimetallic oxide cathode material (MnCeOx@GF) was prepared by hydrothermal method combined with calcination, and the electrochemical Fenton degradation performance of a typical dye Rhodamine B (Rh B) was investigated. The results show that the degradation of Rh B by MnCeOx@GF can reach 96.5 % within 2 h in acidic environment and continue to perform effectively after 4 repeated experiments. Combined with SEM and electrochemical test results, it can be seen that the bimetallic composite oxides formed by manganese and cerium on the surface of the support can effectively enhance the catalytic activity of the material, the addition of cerium changes the morphology of manganese oxides and promotes the generation of multiple valence composite oxides of transition metals, and improves the degradation of Rh B. Based on the free radical masking experiments, hydroxyl radical (·OH) is the main active substance in the electro-Fenton degradation process. This work not only provides a way to design and manufacture cathode materials for in situ electrosynthesis of H2O2, but also provides an important reference for improving the reusability of cathodes for sustainable dye wastewater treatment.

Research progress of Mn-based low-temperature SCR denitrification catalysts.

Selective catalytic reduction (SCR) is a efficiently nitrogen oxides removal technology from stationary source flue gases. Catalysts are key component in the technology, but currently face problems including poor low-temperature activity, narrow temperature windows, low selectivity, and susceptibility to water passivation and sulphur dioxide poisoning. To develop high-efficiency low-temperature denitrification activity catalyst, manganese-based catalysts have become a focal point of research globally for low-temperature SCR denitrification catalysts. This article investigates the denitrification efficiency of unsupported manganese-based catalysts, exploring the influence of oxidation valence, preparation method, crystallinity, crystal form, and morphology structure. It examines the catalytic performance of binary and multicomponent unsupported manganese-based catalysts, focusing on the use of transition metals and rare earth metals to modify manganese oxide. Furthermore, the synergistic effect of supported manganese-based catalysts is studied, considering metal oxides, molecular sieves, carbon materials, and other materials (composite carriers and inorganic non-metallic minerals) as supports. The reaction mechanism of low-temperature denitrification by manganese-based catalysts and the mechanism of sulphur dioxide/water poisoning are analysed in detail, and the development of practical and efficient manganese-based catalysts is considered.

Exposing graphene oxide’s function in enhancing dye sensitized solar cell efficiency

This study aims to explore the potential for increasing the efficiency of the Dye sensitized solar cells through the incorporation of graphene oxide into the titanium dioxide matrix. The presence of defects was observed by Raman spectra. The structural properties and crystallite size of TiO2, GO, and GO/TiO2 composite were investigated using X-ray diffraction analysis, whereas the changes in morphology of graphene oxide and GO/TiO2 were assessed by Field Emission Scanning Electron Microscopy. The presence of functional groups were analyzed by Fourier Transform Infrared Spectroscopy. UV-Visible spectroscopy revealed a reduction in optical bandgap from 3.25 eV for TiO2 to 2.89 eV for GO/TiO2 and optical conductivity were observed increasing from 5.49 × 107 S/cm to 1.19 × 108 S/cm. The efficiency of the fabricated DSSCs was determined through I-V measurement, which showed that the addition of 0.2 wt% of graphene oxide in TiO2 significantly increased the short-circuit current from 0.38 milliampere to 0.75 milliampere, fill factor from 0.71 to 0.82, resulting in a substantial efficiency improvement from 3.99% to 9.11%.

Effect of Cr content on the high temperature oxidation behavior of FeCoNiMnCrx porous high-entropy alloys

FeCoNiMnCr porous high-entropy alloys were prepared using the activation reaction sintering method with Fe, Co, Ni, Mn, and Cr as raw materials. The oxidation behaviors of FeCoNiMnCrx porous high-entropy alloys with different Cr contents, such as pore structure, the surface oxide film phase composition, structure, and morphology, were characterized by X-ray diffraction (XRD), electron probe micro analysis (EPMA), energy dispersive X-ray spectroscopy (EDS), and pore tester after high-temperature oxidation at 800–1000 °C. The results indicate that the initial porous high-entropy alloy comprises a single FCC solid solution phase. With the increase in Cr content, the average pore diameter, average porosity, and air permeability of the porous high-entropy alloy also increase. The oxidation kinetics of the porous high-entropy alloy after exposure to temperatures between 800 °C and 1000 °C follows a single-stage parabolic evolution law. At the same oxidation temperature, With the increase of Cr content, the oxidation gains gradually increased, at the same Cr content at different temperatures, the antioxidant performance of 1000 °C was the weakest, followed by 800 °C, and 900 °C showed excellent antioxidant performance. The oxidation products are mainly Mn2O3, Mn3O4, (Mn, Cr)3O4, Cr2O3and Fe2O3.